萤火工场飞腾派视觉实验:人脸识别

来源: 中电港 2024-10-21 14:31:23
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#机器视觉
飞腾派作为采用国产自主研发的嵌入式处理器的全国产“派”,欲在工业生产落地应用,关于机器视觉的应用是绕不开的,因此本文章将带来飞腾派的机器视觉能力人脸识别测试。

飞腾派是由萤火工场研发的一款面向行业工程师、学生和爱好者的国产自主可控开源硬件。主板处理器采用飞腾嵌入式四核处理器,该处理器兼容 ARM V8 指集,包含2个FTC664 核和2个FTC310 核,其中FTC664 核主频可达1.8GHzFTC310 核主频可达 1.5GHz。主板板载 64 位 DDR4 内存分2G 和 4G 两个版本,支持 SD 或者 eMMC 外部存储。主板板载 WiFi 蓝牙,陶瓷天线,可快速连接无线通信。另外还集成了大量外设接口,包括双路千兆以太网、USB、UART、CAN、HDMI、音频等接口,集成一路 miniPCIE 接口,可实现 A 加速卡与4G、5G 通信等多种功能模块的扩展。

  

主板操作系统支持支持国内 OpenKylin、OpenHarmony、SylixOS.RT-Thread 、Deepin等国产操作系统, 也支持Ubuntu、Debian 等国外主流开源操作系统。

  


准备阶段

飞腾派在使用之前都需要准备一块足够容量的内存卡,并将系统镜像烧入到卡中,以启动“派”,飞腾派支持多种操作系统例如操作Ubuntu、Debian、Yocto、OpenKylin、OpenHarmony、SylixOS.RT-Thread 、Deepin等开源操作系统,本次评测选用基于Debian11的飞腾派OS作为主要开发系统。


设置编译器

 

$ export PATH=$PATH:${YOUR_PATH}/riscv/bin
$ export CC=riscv64-unknown-linux-gnu-gcc
$ export CXX=riscv64-unknown-linux-gnu-g++


模型部分

MNN的使用较为简单,使用方法类似TensorFlow 1.x,简要的流程为:

// 创建会话createSession();// 设置输入getSessionInput();// 运行会话runSession();// 获取输出getSessionOutput();
// 创建会话createSession();// 设置输入getSessionInput();// 运行会话runSession();// 获取输出getSessionOutput();
在该逻辑下,将模型的运行预处理,推理,后处理封装为一个模块:
// ultraFace.hpp#ifndef UltraFace_hpp#define UltraFace_hpp
#pragma once
#include 'MNN/Interpreter.hpp'
#include 'MNN/MNNDefine.h'#include 'MNN/Tensor.hpp'#include 'MNN/ImageProcess.hpp'#include <opencv2/opencv.hpp>#include <algorithm>#include <iostream>#include <string>#include <vector>#include <memory>#include <chrono>
#define num_featuremap 4#define hard_nms 1#define blending_nms 2 /* mix nms was been proposaled in paper blaze face, aims to minimize the temporal jitter*/typedef struct FaceInfo {
    float x1;
    float y1;
    float x2;
    float y2;
    float score;
} FaceInfo;
class UltraFace {public:
    UltraFace(const std::string &mnn_path,
              int input_width, int input_length, int num_thread_ = 4, float score_threshold_ = 0.7, float iou_threshold_ = 0.3,
              int topk_ = -1);
    ~UltraFace();
    int detect(cv::Mat &img, std::vector<FaceInfo> &face_list);
private:
    void generateBBox(std::vector<FaceInfo> &bbox_collection, MNN::Tensor *scores, MNN::Tensor *boxes);
    void nms(std::vector<FaceInfo> &input, std::vector<FaceInfo> &output, int type = blending_nms);
private:
    std::shared_ptr<MNN::Interpreter> ultraface_interpreter;
    MNN::Session *ultraface_session = nullptr;
    MNN::Tensor *input_tensor = nullptr;
    int num_thread;
    int image_w;
    int image_h;
    int in_w;
    int in_h;
    int num_anchors;
    float score_threshold;
    float iou_threshold;
    const float mean_vals[3] = {127, 127, 127};
    const float norm_vals[3] = {1.0 / 128, 1.0 / 128, 1.0 / 128};
    const float center_variance = 0.1;
    const float size_variance = 0.2;
    const std::vector<std::vector<float>> min_boxes = {
            {10.0f,  16.0f,  24.0f},
            {32.0f,  48.0f},
            {64.0f,  96.0f},
            {128.0f, 192.0f, 256.0f}};
    const std::vector<float> strides = {8.0, 16.0, 32.0, 64.0};
    std::vector<std::vector<float>> featuremap_size;
    std::vector<std::vector<float>> shrinkage_size;
    std::vector<int> w_h_list;
    std::vector<std::vector<float>> priors = {};
};
#endif /* UltraFace_hpp */
// ultraFace.cpp
#define clip(x, y) (x < 0 ? 0 : (x > y ? y : x))
#include 'UltraFace.hpp'
using namespace std;
UltraFace::UltraFace(const std::string &mnn_path,
                     int input_width, int input_length, int num_thread_,
                     float score_threshold_, float iou_threshold_, int topk_) {
    num_thread = num_thread_;
    score_threshold = score_threshold_;
    iou_threshold = iou_threshold_;
    in_w = input_width;
    in_h = input_length;
    w_h_list = {in_w, in_h};
    for (auto size : w_h_list) {
        std::vector<float> fm_item;
        for (float stride : strides) {
            fm_item.push_back(ceil(size / stride));
        }
        featuremap_size.push_back(fm_item);
    }
    for (auto size : w_h_list) {
        shrinkage_size.push_back(strides);
    }
    /* generate prior anchors */
    for (int index = 0; index < num_featuremap; index++) {
        float scale_w = in_w / shrinkage_size[0][index];
        float scale_h = in_h / shrinkage_size[1][index];
        for (int j = 0; j < featuremap_size[1][index]; j++) {
            for (int i = 0; i < featuremap_size[0][index]; i++) {
                float x_center = (i + 0.5) / scale_w;
                float y_center = (j + 0.5) / scale_h;
                for (float k : min_boxes[index]) {
                    float w = k / in_w;
                    float h = k / in_h;
                    priors.push_back({clip(x_center, 1), clip(y_center, 1), clip(w, 1), clip(h, 1)});
                }
            }
        }
    }
    /* generate prior anchors finished */
    num_anchors = priors.size();
    ultraface_interpreter = std::shared_ptr<MNN::Interpreter>(MNN::Interpreter::createFromFile(mnn_path.c_str()));
    MNN::ScheduleConfig config;
    config.numThread = num_thread;
    MNN::BackendConfig backendConfig;
    backendConfig.precision = (MNN::BackendConfig::PrecisionMode) 2;
    config.backendConfig = &backendConfig;
    ultraface_session = ultraface_interpreter->createSession(config);
    input_tensor = ultraface_interpreter->getSessionInput(ultraface_session, nullptr);
}
UltraFace::~UltraFace() {
    ultraface_interpreter->releaseModel();
    ultraface_interpreter->releaseSession(ultraface_session);
}
int UltraFace::detect(cv::Mat &raw_image, std::vector<FaceInfo> &face_list) {
    if (raw_image.empty()) {
        std::cout << 'image is empty ,please check!' << std::endl;
        return -1;
    }
    image_h = raw_image.rows;
    image_w = raw_image.cols;
    cv::Mat image;
    cv::resize(raw_image, image, cv::Size(in_w, in_h));
    ultraface_interpreter->resizeTensor(input_tensor, {1, 3, in_h, in_w});
    ultraface_interpreter->resizeSession(ultraface_session);
    std::shared_ptr<MNN::CV::ImageProcess> pretreat(
            MNN::CV::ImageProcess::create(MNN::CV::BGR, MNN::CV::RGB, mean_vals, 3,
                                          norm_vals, 3));
    pretreat->convert(image.data, in_w, in_h, image.step[0], input_tensor);
    auto start = chrono::steady_clock::now();
    // run network
    ultraface_interpreter->runSession(ultraface_session);
    // get output data
    string scores = 'scores';
    string boxes = 'boxes';
    MNN::Tensor *tensor_scores = ultraface_interpreter->getSessionOutput(ultraface_session, scores.c_str());
    MNN::Tensor *tensor_boxes = ultraface_interpreter->getSessionOutput(ultraface_session, boxes.c_str());
    MNN::Tensor tensor_scores_host(tensor_scores, tensor_scores->getDimensionType());
    tensor_scores->copyToHostTensor(&tensor_scores_host);
    MNN::Tensor tensor_boxes_host(tensor_boxes, tensor_boxes->getDimensionType());
    tensor_boxes->copyToHostTensor(&tensor_boxes_host);
    std::vector<FaceInfo> bbox_collection;
    auto end = chrono::steady_clock::now();
    chrono::duration<double> elapsed = end - start;
    cout << 'inference time:' << elapsed.count() << ' s' << endl;
    generateBBox(bbox_collection, tensor_scores, tensor_boxes);
    nms(bbox_collection, face_list);
    return 0;
}
void UltraFace::generateBBox(std::vector<FaceInfo> &bbox_collection, MNN::Tensor *scores, MNN::Tensor *boxes) {
    for (int i = 0; i < num_anchors; i++) {
        if (scores->host<float>()[i * 2 + 1] > score_threshold) {
            FaceInfo rects;
            float x_center = boxes->host<float>()[i * 4] * center_variance * priors[i][2] + priors[i][0];
            float y_center = boxes->host<float>()[i * 4 + 1] * center_variance * priors[i][3] + priors[i][1];
            float w = exp(boxes->host<float>()[i * 4 + 2] * size_variance) * priors[i][2];
            float h = exp(boxes->host<float>()[i * 4 + 3] * size_variance) * priors[i][3];
            rects.x1 = clip(x_center - w / 2.0, 1) * image_w;
            rects.y1 = clip(y_center - h / 2.0, 1) * image_h;
            rects.x2 = clip(x_center + w / 2.0, 1) * image_w;
            rects.y2 = clip(y_center + h / 2.0, 1) * image_h;
            rects.score = clip(scores->host<float>()[i * 2 + 1], 1);
            bbox_collection.push_back(rects);
        }
    }
}
void UltraFace::nms(std::vector<FaceInfo> &input, std::vector<FaceInfo> &output, int type) {
    std::sort(input.begin(), input.end(), [](const FaceInfo &a, const FaceInfo &b) { return a.score > b.score; });
    int box_num = input.size();
    std::vector<int> merged(box_num, 0);
    for (int i = 0; i < box_num; i++) {
        if (merged[i])
            continue;
        std::vector<FaceInfo> buf;
        buf.push_back(input[i]);
        merged[i] = 1;
        float h0 = input[i].y2 - input[i].y1 + 1;
        float w0 = input[i].x2 - input[i].x1 + 1;
        float area0 = h0 * w0;
        for (int j = i + 1; j < box_num; j++) {
            if (merged[j])
                continue;
            float inner_x0 = input[i].x1 > input[j].x1 ? input[i].x1 : input[j].x1;
            float inner_y0 = input[i].y1 > input[j].y1 ? input[i].y1 : input[j].y1;
            float inner_x1 = input[i].x2 < input[j].x2 ? input[i].x2 : input[j].x2;
            float inner_y1 = input[i].y2 < input[j].y2 ? input[i].y2 : input[j].y2;
            float inner_h = inner_y1 - inner_y0 + 1;
            float inner_w = inner_x1 - inner_x0 + 1;
            if (inner_h <= 0 || inner_w <= 0)
                continue;
            float inner_area = inner_h * inner_w;
            float h1 = input[j].y2 - input[j].y1 + 1;
            float w1 = input[j].x2 - input[j].x1 + 1;
            float area1 = h1 * w1;
            float score;
            score = inner_area / (area0 + area1 - inner_area);
            if (score > iou_threshold) {
                merged[j] = 1;
                buf.push_back(input[j]);
            }
        }
        switch (type) {
            case hard_nms: {
                output.push_back(buf[0]);
                break;
            }
            case blending_nms: {
                float total = 0;
                for (int i = 0; i < buf.size(); i++) {
                    total += exp(buf[i].score);
                }
                FaceInfo rects;
                memset(&rects, 0, sizeof(rects));
                for (int i = 0; i < buf.size(); i++) {
                    float rate = exp(buf[i].score) / total;
                    rects.x1 += buf[i].x1 * rate;
                    rects.y1 += buf[i].y1 * rate;
                    rects.x2 += buf[i].x2 * rate;
                    rects.y2 += buf[i].y2 * rate;
                    rects.score += buf[i].score * rate;
                }
                output.push_back(rects);
                break;
            }
            default: {
                printf('wrong type of nms.');
                exit(-1);
            }
        }
    }
}

  

看起来运行效果相当不错,仅需55ms左右即可完成推理!

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